Search published articles


Showing 2 results for Tribology

N. Nikoogoftar, S. H. Razavi, M. Ghanbari,
Volume 14, Issue 3 (9-2017)
Abstract

In this research, the effect of annealing and aging temperature as well as the effect of quenching media on the microstructure, hardness and dry sliding wear behavior of Ti-6Al-4V alloy has been studied. Cylindrical samples with the diameter of 10 mm and the height of 20mm were solutionized at 930˚C and 1060˚C for 600 seconds and then were quenched in the cold water and in the air. The samples were aged at different temperature of 480˚C, 550˚C and 610˚C for 360 s to increase the hardness. Heat treated samples were tested using standard pin-on-disc test machine at the applied loads of 100, 150 and 200 N. Microstructural investigations using scanning electron microscope revealed that for the samples solutionized at 930˚C and quenched in the water, the microstructure is composed of primary α and high volume fraction of martensitic α΄ phase with fine precipitated of β between martensitic lathes. In the case of air cooled samples, transformed β has also been  appeared in the vicinity of primary α. For the samples solutionized at 1060˚C and quenched in the water, fully martensitic micro structure with fine β precipitates was observed. For the sample solutionized at 1060˚C and air quenched, plate like α and lamellar grain boundary β were detected. The maximum hardness value relates to the sample solutionized at 1060˚C and quenched in water which is equal to 433 HV. Different wear mechanisms, including oxidative wear, scratch, and delamination occurred at the worn surfaces at different applied loads. For the samples quenched in the water, the oxidative wear mechanism governing at low applied load and oxide debris was observed as separate or compacted particles which formed in the contact between pin and steel counter face detached from the sample. At higher applied loads, delamination and scratch mechanism was also observed and metallic plate like debris was detached from the sample. Mechanically mixed layer (MML) was formed on the surface of the pin at high applied loads and for the samples with low hardness value adhesion marks were also revealed on the steel disc. The minimum weight loss in the wear test is related to the sample quenched from the 1060ºC in the cold water and aged at 550 ºC .  


Sh. Keshavarz, M. R. Naimi-Jamal, M.gh. Dekamin, Y. Izadmanesh,
Volume 17, Issue 4 (12-2020)
Abstract

In this work, the facile synthesis and identification of hexylmethylimidazolium bis(trifluoromethyl­sulfonyl)­amide ([HMIM]­TFSA) and hexylmethylimidazolium triethyltrifluorophosphate ([HMIM]FAP) ionic liquids (ILs), as multifunctional and multipurpose gear oil additives, is introduced. The tribological tests indicated that both ([HMIM]TFSA) and ([HMIM]FAP) ILs demonstrate antiwear/extreme pressure properties (AW/EP) to the gear oils by preventing wear and scar of the lubricated system at low and high temperatures. [HMIM]TFSA provided superior performance in comparison to [HMIM]FAP. Because of the presence of heteroaromatic imidazole moiety in the ILs structure, the prepared ILs also imparted anticorrosion, antioxidant, and anti-rust properties to the lubricant. All these observations confirmed that the ILs are single component multifunctional and multipurpose oil additives. In addition, due to avoiding the use of toxic and harmful elements in the preparation of ILs make the fabricated oils potential candidates for green lubricants.

Page 1 from 1     

© 2022 All Rights Reserved | Iranian Journal of Materials Science and Engineering

Designed & Developed by : Yektaweb